BIOCATALYTIC CONVERSION OF BIOMASS TO BIOFUELS

Abstract

Biological conversion of biomass to biofuels has been extensively reviewed. In this experimental work sugarcane bagasse was used as biomass and ethanol was the biofuel. The biological process of ethanol production using bagasse as substrate requires: (1) Pretreatment: depolymerization of the carbohydrate polymers (cellulose and hemicellulose) to produce free sugars, and (2) Fermentation: fermentation of mixed hexose and pentose sugars to produce ethanol. Acid hydrolysis was conducted as pretreatment of bagasse with 2% H2SO4 solution at residence times of 60, 90 and 120 min. 28.0125 g/L of glucose and 560.07 mg/L of furfural were obtained in 1st hydrolysis of bagasse at 120 min residence time. Several detoxification processes were used to remove / reduce the furfural concentration. Three times extraction of bagasse hydrolysate with ethyl acetate was carried out, and it removes 91.02 % of furfural with less removal of glucose (9.34%). Batch fermentation was carried out with two strains, one was GNSA strain and another was IIPE453 strain. GNSA strain was grown in H1 medium at 60 °C and IIPE453 strain was grown in H2 medium at 45 °C. The highest product yield of 21.6% was obtained with IIPE453 strain at 6 hrs operation_